Thermal safety control mechanism



Feb. 14, 1928.

W. W. WILLIAMS THERMAL SAFETY CONTROL MECHANISM Filed April 14, 1922 2 Sheets-Sheet Watnames THERMAL SAFETY CONTROL MECHANISM Filed April 1 1922 2 snee ts-sheez 2 fl a'tnexes fnuenzian Patented Feb. 14,1928.

I UNITED sTA Es 2 1,659,536 PATENT QFFICE.

' WALTER W. WILLIAMS, OI BLOO KS 'INGTON, ILLINQIIS, ASSIGNOR 1'0 WILLIAMS OIL-O- MATIC HEATING CORPORATIQN; OF BLOOMINGTON, ILLINOIS, A GORPORATION OF ILLINOIS.

THERMAL SAFETY CONTROL MECHANISM.

Applicatlon flled April 14, 1922. semi No. 552.816.

-My invention relates to safety, control mechanisms in connection with llqllld"fu8l' feeding devices. I

The Object of y Invention is vision of a safety means for controlling theaction of a liquid fuel burning device; said mechanism being responsive and-{controlled by the heat ivenoif by the pilot light;

' Another 0 ject of my invention is inthe 10 provision of a thermal safety mechanism I cont-rolled by the pilot light, saidgcfontrolf means consisting of an electrical" contact mechanism having aportion thereof, formed" of bi-metallic metal, said ortion capable of;

making or breaking an e ectric circuit g he expansion or retraction thereof, caused by the heat given off. by the pilots-Q filed September 17 1921, I,have2 described 20 and claimed generally a safet mechanism controlled by the heat given' o by the pilot light. However, inzthat instance I relied upon the expansion or retraction of a dia- P ragm, under varyingheat pressures, to ac- 5 complish my result.

cation I have provided means for accomplishing the same result, that is, of safety control but in a somewhat different manner.

Other objects of myinvention will appear in the following specification in connection with the annexed drawings in.which:

Figure 1, is a general viewofthe combination including the liquid fuelburning device and safety control mechanism, including the electrical circuit, therefor, v

I Figure 2, is an enlarged detail in plan of my specific thermal contact member.

Figure 3, is a side elevation thereof. Figura is an end elevation of Figure 3 and 40 Figure 5, is a plan view from below of the contact member. Referring to the drawings, a liquid fuel burning device is shown generally; at .a,

4 this device having been described in detail in my Patent No. 1,451,798, dated April 17 1923. It.,may be said generally that a series of pumps discharge an atomized fuel mixture from the jet 10. The above general statement as to thedischarge of the atomized fuelmixture from the jet 10 must necessarily include a more detailed explanation as to structure utilized therefor, although said subject matter forms the basis of said Patent n my present appli-Y 1,451,798 The liquid fuel is drawn thru the fuel tube 10 into a. rotary pressure pump .10" and raised to a considerable pressure therein before discharge thru the fuel tube plies power for the rotary pressure pump air blast to produce a properly and efficient- 1y atomized-fuel mixture.

My'present application is dire cted to the Q'means for igniting this fuelmixture and for controllin the action of thedevice under all condltlons. In my device I have always used a gas pilot-lighfifor igniting the fuel v mixture and it is in connection with this In my co-pending applicatlon No. 501,486,;

pilot ,1ight' t hat I have combined my present safety control means It is {wellknown in the burnerart and especially in plants used in the heating of houses that some safety means must be used therefor. Mechanical means controlled by an overflow of fuel oil in case of non-ignition have-been used, and also mechanism controlled by combustion conditions or rather, thefailure of combustion conditions. In my former application No; 501,486 and in the present. one I have combined my safety means with the pilot light and have provided mechanism Which is controlled by an element-which is absolutely essential to the operation of the device.

11 shows a tube attached to tional gas;supply,;and a second gas tube 12 connectsthis supply with my specific thermal contact member which is-shown in the detail figures OnHSheet two of the drawings. Generally'this thermal contact member described as a in Figure lis disposed in an angular relation tothe discharge nozzle Whereupon the gas flame therefrom is projected into the cone vofthe fuel discharges The gas tube 12- has threaded connection at its-"outer end with the cap 18 on the thermal contact member. This cap projects into the base l i of said member and has a small gas connection or jet 15 with a coned inner portion 16 of said base.

As may be seen in Figurel, the thermal contact member has this coned portion or jet disposed angularly with relation to the fuel discharge nozzle, and the contact portions of the said thermal device project the conven- 10 to the jet 10. An electric motor 10 sup-.

rearwardly or rather are housed within the general housing of the blast tube of the burner. The base portion 14 has integrally cast therewith and projecting rearwardly therefrom a plate 17. Projecting through and fixedly mounted at the rear end of this plate is a contact screw 18 supported and insulated by means of the nuts 19 and insulating material 20 respectively. A contact arm is attached to the plate 17 as at 21. This contact member is formed of thermostatic metal and has a contact portion 22 at its outer end capable oi engaging the screw member 18. A. guard 24 surrounds a major portion of the late and on the inner side of this guard 18 a strip of mica 25. This special guard means for the plate member and contact points prevents the etfects of temperature variations on the thermal contact members.

The above specific thermal contact portion operates in the following manner:

The flame from the gas jet heats the walls of the coned portion 16 and therefore the base portion. This metal is-a good conductor of heat and therefore the heat is transmitted directly to the plate which is in connection with the contact arm 21. The action of this heat upon the iii-metallic contact arm, is to raise said contact arm to the dotted line position shown in Figure 3 and to hold it in such position as long as the pilot light has its flame projecting against the coned portion of the base. Likewise failure of the pilot light results in a cooling of the base and therefore the contact arm, with the result that said arm contracts and its point makes contact with the insulated screw contact member.

So far I have said nothing of the electrical circuit which is included in the combination with my safety control means. Inasmuch as these various electrical elements have been partially shown and described in my co-pending application No. 501,486 I do not deem it necessary to go into too great a detailed description'thereof.

The time switch T has a vertically positioned heating coil 36 which is supported by the mounting plate 37. A spring lever 38 composed of any thermal or bi-metallic metal is attached as at 39 to a bracket member 40. The upper end of the lever 38 rides beneath a lug 41 on a horizontally disposedcontact arm 42 firmly positioned as at 43. The outer end of the contact lever has the usual contacts 44 and 45 which have possible engagement with similar contact members 46 and 47.

It may be said at this time relative to the co-operation of the commercial transformer X, electrical relay switch R and fuel atomizi device 10", that two electrical circuits are utilized, one being a high voltage circuit which includes the fuel atomizing device,

circuit to the atomizing device, and alsothe commercial room thermostat which includes the relay switch and hence controls the operation of the device directly from temperature conditions.

The operation of my device is as follows:

Figure 1 of the drawings illustrates the position assumed by the parts when the liquid fuel is burning at the nozzle and the room thermostat has just been moved by the temperature of the room to shut off the burner. When the liquid fuel is burning at the nozzle, the circuit between leads 26 and 27 is broken through Z. When the movable contact arm of the thermostat engages the right-hand contact, as shown, the secondary circuit is completed and the current travels from the left-hand terminal at the bottom of the transformer X, through a lead to a bindin postupon the heat switch T directly below the transformer. From thence it passes through the movable horizontal arm 42 of the heat switch T to the upper left-hand contact 46 which it is shown to engage, and from thence through the lead shown in dotted line connected to the binding post second from the right at the top of the panel, and thence through the lead to the connection to the movable'arm of the thermostat Y, the lower end of the movable arm hein in engagement with the righthand bin in post at the top of the panel, and from t ence through the dotted line lead, through the coils of the right-hand electromagnet 52 of the relay R and from thence through the dotted line lead to the stationary contact below that magnet. With the position of the armature arm 55 as shown, the contact on the extension 60 from the under side thereof, on the lower side of the pivot, is in engagement with the righthand stationary contact 61 below the righthand magnet, so that the secondary current passes through this extension through the metal cap at the end of the arm to the metal plate between the magnets and panel which is shown secured to the panel by the two screws appearing between the electromagnets on each side of the armature arm. The current then passes from the plate through the lead shown in dotted lines extending from the left-hand screw to the right-hand terminal of the transformer. The secondary current following this path energizes the right-hand electromagnet 52 which attracts the armature arm 55 of the relay, causing it to rotate about its pivot and break the contact at the top of the arm which is shown engaging the fixed contact 59 in theline circuit, and thereby breaking the circuit to the motor. At the same time this rotative movement of the armature arm about its pivot breaks the secondary circuit, as well,

of the thermostat to move to the left andcomplete the connection with the left-hand contact member, the secondar circuit follows thepath from thetrans ormer to the movable contact arm of the thermostat Y, as

heretofore described. The secondary ci'rcuit' then passes through the lead from the lefthand contact of the thermostat to the third binding post from the right at the top of the panel board and from thence through the dotted line lead to the left-hand electromagnet 51 of the relay B, through the magnet, and through the dotted line lead to the stationary contact below that magnet. The position of the armature arm when the burner is shut off moves the depending contact 60 carried thereon into enga ement with the stationary contact 62 below t e left-hand magnet, so that the current then passes through this depending arm to the metal plate upon which the electromagnets are mounted and through the dotted line lead from the left-hand screw of said plate to the right-hand terminal of the transformer Z. The energizing of the left-hand magnet 51 draws the armature arm over into the position shown in Figure 1, the motor circuit is thereby closed and the burner begins to function and the secondary circuit is a ain broken by the movement of the depen ing contact.

' When the pilot light is extinguished, the thermostatic member 21 of Z contracts and closes the circuit between-leads 26 and 27 through the ground. If the room thermostat closes the secondary circuit to start the operating of the burner in the manner described when the gas pilot is extinguished then the burner flame fails to ignite, and a part of the current of the secondary circuit will pass from the binding post upon the heat switch T through the heating coil 36 directly below said bindlng 0st, through lead 26, thermostat Z, ound, to lead 27, thence to the right-ban stationary contact 61 in the lower part of the fpanel, through the depending contact 60 o the armature arm through the metal plate and lead shown in dotted lines from the lefthand screw to the right hand terminal of the transformer X. The closing of this circuit through the heating coil will cause the thermostatic member 38 at the left thereof to deform and release the support 41 below the horizontal contact arm 42 so that it will break theyconnection between the upper left-hand contact 46 of the heating switch and. close the connection between the binding 0st at the right-hand of the heat switch t rough this movable horizontal contact arm 42 to the lower binding post on the left-hand side. The current then passes from this binding post through the dotted line lead to theright-hand binding post on the top of the panel and thence downward through the dotted line lead to the right-hand electromagnet 52 and thereby draw the armature arm to the right and break the motor circuit. During the normal operation of the burner should at any time the ilot and burner flame become extinguished, tlie thermostatic member 21 of Z will cool and contract closing the secondary circuit between leads 26 and 27, whereby the heating coil 36 will be" energized and cause the heat switch to energize the right-hand magnet and break the motor circuit.

It is easily seen that before the burner can continue its operation the ilot light must. be

relighted and the time switch reset.

What I claim is:

1. In a liquid fuel burning system com-- prlsmg electrical operating means for pro-- jecting air and sprayed fuel into a zone of ignition, means for igniting the fuel, a high voltage circuit including said fuel projecting means, a low voltage circuit, anelectrically controlled device in said low voltage circuit for making and breaking the circuit of the said fuel projecting means, and a room thermostat included insaid low voltage circuit and having a movable member forcontrolling the circuit to said electrically-controlled device whereby according to the degree of temperature in the room the circuit of said device will be controlled by said thermostat to cause said device to break the circuit to the fuel projecting means or to close said circuit.

2. In a liquid fuel burning systemcomprising electrically operated means. for projectlng air and sprayed liquid fuel into a zone of ignition, means for igniting the fuel,

a high voltage circuit including said fuel projecting means, a low. voltage circuit, a magnet switch for making and breaking the circuit of said fuel projecting means, the magnets whereof are in said low voltage circuit, and a room thermostat included in said low voltafge circuit and having a movable member or controlling the circuiti't'o the magnets of said switch whereby according to the degree of temperature in the room, the circuit to said magnet switch will be controlled by said thermostat to cause said switch to break the circuit to the fuel pro jecting means or to close said circuit.

3. In an oil burningheating system, electrically operated means for projecting air and sprayed liquid fuel into a zone of ignition, means for igniting the fuel, a high I voltage circuit including said fuel projecting means, a low voltage circuit, an electricall controlled device in said low voltage circuit for making and breaking the circuit of said fuel projecting means, and a room thermostat connected to one side of said 10w voltage circuit and having a movable member for controlling the circuit to said electrically controlled device whereby, according to the degree of temperature in the room, the circuit to said device will be controlled by said thermostat to cause said device to break the circuit to the fuel projecting means or to close said circuit.

4. In an oil burning heating system, electrically'operated means for projecting air and sprayed liquid fuel into a zone of ignh -\trolled by said thermostat to cause said switch to break the circuit to the .fuel projecting means, or to close said circuit.

In testimony whereof I afiix my signaturef WAl'JTER W. WILLIAMS. 

